1. Field of the invention

The present invention relates to engineering plastic blends and composites. More particularly, the present invention relates to hybrid carbonaceous biocomposites, and more particularly to polyamide (PA) and engineering polyester-based carbonaceous biocomposite blends with high sustainable and recycled content, enhanced dimensional stability and durability for high performance applications, particularly those requiring high tolerances for injection moulding.

2. Background of invention

Polyamides (PAs), commonly known as nylons, are a well-established class of engineering thermoplastic, which are widely used in many industrial applications, including the automotive sector. Nylons such as PA6 and PA6,6 are especially desirable materials for automotive use due to their excellent strength, stiffness, thermal stability, and resistance to chemicals and abrasion. A common practice in industry for modifying the properties of nylons is their blending with other thermoplastics (such as polyethylene, polypropylene, and polystyrene) and elastomers.

When combined with reinforcing fillers such as glass fibers and minerals (ie; talc, kaolin, wollastonite), nylon composite resins can be produced with exceptional stiffness, while maintaining processability in injection moulding applications. This has facilitated the replacement of steel and aluminum automotive parts with nylon composite resins, which has allowed weight savings due to the lower density and higher specific strength of the material. These resins have been especially effective in“under-the-hood” applications due to their excellent durability and heat resistance. Chinese Patent CN103087515B discloses a high-content glass fiber reinforced PA6 composite material and preparation method thereof. The designed PA6 composite prepared according to the stated invention has excellent performance, particularly having good mechanical properties.

The reinforcement of PA resins with clay particles has been a heavily researched area in the last 20 years. Of particular interest is the development of organically modified clays, or organoclays, which can be exfoliated in situ during extrusion with PAs. The exfoliation separates the individual clay platelets, yielding a nanoscale dispersed reinforcement with a high aspect ratio. The achievement of PA-organoclay nanocomposites has led to drastically improved properties at a low filler loading (less than 5%), including the tensile strength, modulus, heat deflection temperature (HDT) and coefficient of linear thermal expansion (CLTE). A substantial amount of research effort by various academic and industrial projects has investigated the mechanical, thermomechanical, rheological, and tribological properties of nylon-clay nanocomposites. ^{1 7} The suitability of these nanocomposites for automotive components has driven their development and application in this industry. ^{8, 9}

Biosourced carbon (biocarbon) has seen recent development as a carbonaceous reinforcing filler for engineering thermoplastics. Due to its high temperature stability, it is compatible for extrusion at elevated temperatures, while also being completely bio-based. Because biocarbon can be a carbon sink and is produced from a variety of organic materials, it is an ideal low-cost filler with reduced environmental impact compared to existing fillers such as talc and glass fiber. Recent studies of biocarbon composites have shown that it can successfully reinforce a variety of polymers, while also providing reduced weight compared to mineral-filled composites without compromising performance. ^{10 15} Ogunsona et al. have conducted research specific to PA- biocarbon biocomposites, which have demonstrated that biocarbon (at loadings of 20-30 wt.%) can successfully improve the tensile strength, stiffness, and HDT of PA6, while maintaining good processability in injection moulding equipment. ^{16 18} High performance biobased PA6- polypropylene blends and their biocomposites [US20180022921] have been reported by Mohanty et al. The nylon-based biocomposites possess decent performance and at the same time are light weight.

One of the remaining challenges in commercializing this biocomposites is controlling its CLTE. This aspect is critical in order to ensure the proper dimensional tolerances are achieved in the injection moulds used within industry and to predict the degree of post-moulding shrinkage.

Biobased composites (biocomposites) usually have little resistance to environmental degradation when compared to synthetic fibers due to their natural constituent portion in the system. Therefore, the improvement of the durability and lifetime of the biocomposites under severe environmental conditions remains a challenge yet to be solved. A further challenge is controlling the thermal degradation of the material during prolonged exposure to elevated temperatures - polyamides are well known to be susceptible to both oxidative and hydrolytic aging processes. The blending of polyamide with thermally stable engineering thermoplastics might boost its durability performance. These composite resins possess high degrees of tensile and flexural strength/stiffness, impact resistance, and are resistance to thermal aging effects.

Polybutylene terephthalate (PBT) is another essential high-volume engineering thermoplastic belonging to the same polyester family as polyethylene terephthalate (PET). PBT is highly used in many industrial applications ranging from household components to automotive parts due to its excellent properties. In particular, unreinforced and reinforced PBT are heavily used as automotive components due to its high mechanical strength, dimensional stability, high heat distortion temperature, durability, etc. These outstanding properties make PBT one of the blend candidates by researchers with many polymers to improve performance. This includes blending PBT with PET, polystyrene (PS), PA6,6, PP, polycarbonate (PC), polyether imide (PEI) and others. Our recent published works showed that the blending of PA6 and PBT showed exceptional mechanical performance. The mechanical strength is higher than their neat polymer after blending at 90/10 and 80/20 PA6/PBT composition. The amide-ester reactions might occur during the reactive extrusions of the blends, which can yield good benefits to the PA6-based blends and composites performance.

Chinese patent CN103073853B describes an environmentally friendly flame retardant reinforced PBT/PET/PA6 alloy and preparation method. The alloy is composed of PBT, PET, PA6, toughening compatibilizer compound type, flame retardant synergists, glass fibers, antioxidants and lubricating dispersion agent.

PA6 and polyesters like PET and PBT are immiscible in nature when blending. ^{19, 20} Compatibilization of the blends with reactive chemical compound are necessary to improve the blends’ interactions and performance. Han et al. ²¹ compatibilized PA6 and PBT with an appropriate amount of ethylene glycidyl methacrylate and they reported significant improvement in the tensile strength after compatibilization. Other published works on the compatibilization of PA6 and PBT have been reported with different grafting approaches such as using ethylene-vinyl acetate grafted maleic anhydride (EVA-g-MA), PA1 l-g-MA ¹⁹ etc.

The use of sustainable materials and utilization of waste/recycled products in many commercial products has increased tremendously due to the environmental concern globally. The use of these sustainable materials helps in addressing global concern such as environmental pollution, global warming as well as climate change. A number of patent documents have been filed and reported to develop sustainable biocomposites with natural materials from plant fiber, biochar, cellulose, bacteria nanocellulose etc. i.e. US9809702B2, US8877338B2, CN105086328B, CN104693606B, US8541001B2. Innovative sustainable resources such as biosourced materials, as well as wastes, coproducts, and recycled materials, can be used as both the matrix and reinforcement in composites to minimize the use of non-renewable resources and to make better use of waste streams. Recycled water bottle (a.k.a. recycled PET) and recycled carpet (a.k.a. recycled nylon) from the wastes are two sustainable alternatives to new petroleum sourced plastics. The proper utilization of recycled materials can reduce humans needs on heavily relying on the finite petrol-sourced resources.

Carpet waste is one of the largest postconsumer wastes in the world. Due to the complex composition and additives present in floor carpet, the carpet wastes are not suitable for direct reuse in textile processing. ²² Carpet wastes could be potentially used for polymer blends or composites reinforcement after being properly ground and processed.

From the food packaging sector, a significant amount of PET ends up in the recycling stream, with PET being one of the most widely recycled plastics. This recycled PET (rPET) has found many uses in reprocessed areas from fiberfill, to fabric, to automotive parts, to industrial strapping, sheet and film, and new containers for both food and non-food products. However, rPET tends to undergo hydrolysis when it is reprocessed, which decreases its average molecular weight (MW). Other factors during PET’s recycling can also contribute to MW loss, such as thermal exposure and shear degradation. The rPET plastic then available for product manufacturing has reduced mechanical properties, impact resistance, and melt viscosity. This shrinks its useful scope compared to virgin PET. 3. Summary of invention

The present invention provides a reinforced polyamide-based resin with high sustainable content, including recycled content and biobased additive, which also demonstrates thermal stability during extrusion processing, and a degree of dimensional stability that is suitable for injection moulding applications demanded by industry.

In one embodiment, the present invention is a biocomposite formulation comprising a polyamide, an engineering polyester and biocarbon.

In one embodiment of the biocomposite formulation of the present invention, the engineering polyester is polytrimethylene terephthalate (PTT), polyethylene terephthalate) (PET), polybutylene terephthalate (PBT) or any combination thereof.

In another embodiment of the biocomposite formulation of the present invention, the polyamide is PA6, PA6,6 or a combination thereof.

In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation further comprises a recycled polymer.

In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation comprises at least 20 wt.% of the polyamide, at least 10 wt.% of the recycled polymer, at least 10 wt.% of the engineering polyester and at least 15 wt.% of the biocarbon.

In another embodiment of the biocomposite formulation of the present invention, the recycled polymer is a recycled polyamide, a recycled engineering polyester, or a combination of a recycled polyamide and a recycled engineering polyester.

In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation comprises at least 20 wt.% of the polyamide, at least 10 wt.% of the recycled polyamide, at least 10 wt.% of the recycled engineering polyester and at least 15 wt.% of the biocarbon.

In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation further comprises a nanofiller. In aspects of the invention, the biocomposite formulation comprises up to 3 wt.% of the nanofiller

In another embodiment of the biocomposite formulation of the present invention, the nanofiller is nanoclay.

In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation further comprises maleated polypropylene (MAPP) or maleated polyethylene (MAPE) compatibilizer.

In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation further comprises acrylate ethylene terpolymer (EBA-GMA).

In another embodiment of the biocomposite formulation of the present invention, the biocmposite formulation further comprises 1 to 3 wt.% of MAPP and/or MAPE, 1 to 2 wt.% MAPE, 1 to 2 wt.% SMA and 3 to 6 wt.% EBA GMA compatibilizers.

In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation further comprises recycled carbon fiber.

In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation further comprises pultruded long carbon fiber master batch.

In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation further comprises PLA. In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation has a notched impact strength equal to or more than 60 J/m;

In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation has tensile strength equal to or more than 100 MPa and a tensile modulus equal or more than 9000 MPa.

In another embodiment of the biocomposite formulation of the present invention, the biocomposite formulation has a density equal to or more than 1.26 g/cm ³ .

In another embodiment of the biocomposite formulation of the present invention, the recycled polymer content is at least 20% of the total mass of the biocomposite.

In another embodiment of the biocomposite formulation of the present invention, the recycled polymer and biocarbon content is at least 50% of the total mass of the biocomposite.

In another embodiment of the biocomposite formulation of the present invention, the biocarbon is a hybrid biocarbon comprising two or more different biomass sources.

In another embodiment of the biocomposite formulation of the present invention, the biocarbon is a hybrid biocarbon comprising a mixture of biomass sources of different temperatures of pyrolysis.

4. Detailed description of the invention

4.1 Definitions

The following definitions, unless otherwise stated, apply to all aspects and embodiments of the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Also, unless indicated otherwise, except within the claims, the use of“or” includes“and” and vice versa. Non-limiting terms are not to be construed as limiting unless expressly stated or the context clearly indicates otherwise (for example“including”,“having” and “comprising” typically indicate“include without limitation”). Singular forms included in the claims such as“a”,“an” and“the” include the plural reference unless expressly stated otherwise. All relevant reference, including patents, patent applications, government publications, government regulations, and academic literature are hereinafter detailed and incorporated by reference in their entireties.

All numerical designations, including ranges, are approximations which are varied (+ ) or ( - ) by increments of 1.0 or 0.1, as appropriate, or alternatively by a variation of +/- 15 %, or alternatively 10%, or alternatively 5% or alternatively 2%. It is to be understood, although not always explicitly stated, that all numerical designations are preceded by the term“about”. It also is to be understood, although not always explicitly stated, that the reagents described herein are merely exemplary and that equivalents of such are known in the art.

As used herein, the term“substantially” includes exactly the term it modifies and slight variations therefrom.

The term“plurality,” as used herein, is defined as two or more than two. The term“another,” as used herein, is defined as at least a second or more. The phrase“at least one of ... and ...” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. As an example, the phrase“at least one of A, B and C” includes A only, B only, C only, or any combination thereof (e.g. AB, AC, BC or ABC). The term“substantially” includes exactly the term it modifies and slight variations therefrom. The term“about” modifying any amount refers to the variation in that amount encountered in real world conditions of producing materials such as polymers or composite materials, e.g., in the lab, pilot plant, or production facility. For example, an amount of an ingredient employed in a mixture when modified by about includes the variation and degree of care typically employed in measuring in a plant or lab and the variation inherent in the analytical method. Whether or not modified by about, the amounts include equivalents to those amounts. Any quantity stated herein and modified by“about” can also be employed in the present invention as the amount not modified by about.

Non-limiting examples of“engineering polyester” include polytrimethylene terephthalate (PTT), poly(ethylene terephthalate) (PET) and polybutylene terephthalate (PBT).

“Biocarbon” refers to the solid carbonaceous material, also referred to as charcoal or biochar, obtained through pyrolysis of biomass that contains plant fiber (including miscanthus, wood chips, corn cob, soy hulls, peanuts hulls and chicken feather, etc.) at the pyrolyzing temperatures between 350 to 900 °C, in the absence or near absence of oxygen.

The prefix“bio-” is used in this document to designate a material that has been derived from a renewable resource.

“Master batch”, as used herein, refers to a mixture or blend of filler (e.g. biocarbon, carbon fiber) and plastic, typically prepared by extrusion, which is added to a plastic to form the final composite. The master batch can be used to control the dosage and dispersion when added in the desired ratio during extrusion or injection molding of the final composite materials. The master batch may contain one or more additives, such as lubricants. “CLTE” refers to coefficient of linear thermal expansion, a measure of the degree of expansion of a material for a measured change in temperature.

“HDT” refers to heat deflection temperature (or heat distortion temperature), a measure of the temperature at which a material deforms under a specified load.

“Composite” refers to any polymer matrix which is reinforced with a dispersed filler material.

“Biocomposite” refers to a composite in which some fraction of the material, either the polymer or filler, is bio-based or/and recycled plastics or recycled carbon fibers.

“Nanocomposite” refers to any composite material in which a dispersed phase with at least one dimension on the nanometer scale is present (e.g. Nano clay).

The term“wt.%” refers to the weight percent of a component in the composite formulation with respect to the weight of the whole composite formulation.

The term“phr” refers to the parts per hundred of a component in the composite formulation with respect to the part of the whole composite formulation.

4.2 Overview

The present invention relates to engineering plastic composites with high sustainable content. The source of the sustainable content include biobased content, recycled content and waste content.

Plastic composites are generally hindered when incorporating multiple sustainable materials as those mentioned. The present invention addresses the shortcomings of the prior art by enhancing nylon-biocarbon blends with nanofillers, creating nanocomposites with enhanced dimensional stability, stiffness, and thermal stability (HDT). Biocarbon is a sustainable, bio-based material which has proven to be a lightweight, thermally stable reinforcing filler for polyamide-based composites. By enhancing the blend with nanoclay, a hybrid reinforcement system is created which provides excellent mechanical properties while only requiring a small fraction of clay, and maintaining a high degree of bio-based content. These nanocomposites have improved thermal and dimensional stability, as well as enhanced tensile and flexural properties.

The tensile and flexural properties are further improved by the addition of recycled chopped carbon fiber. The use of post-industrial recycled short fibers provides a cost effective and more sustainable solution to dramatically increase the tensile and flexural strength/modulus of the resins. The recycled carbon fibers can be added in the end zones of the compounding process to retain the structural integrity of the fibers. The incorporation of the long-fibers can occur in the secondary step when conducting the injection molding stage giving rise to improved properties through retention of aspect ratio and limited breakage.

Finally, blending of the nylon matrix with an additional polymer, poly(butylene terephthalate) (PBT) or poly(ethylene terephthalate) (PET), is used to provide improved thermal durability to counteract the susceptibility of nylon to oxidative degradation at elevated temperatures. These polymers are immiscible, but several studies have shown that compatibilization can be achieved using functional epoxy compatibilizers. ^{20, 23-25} In this invention, a unique approach is taken to compatibilize the blend using a maleated polypropylene additive, in concert with an ethylene- acrylate copolymer additive to enhance the toughness. Maleated copolymers are conventionally used in polyamide blending with aliphatic polymers, however in this case of compatibilizing nylon and PBT or PET, the use of a maleated polypropylene is novel. To the best of the authors’ knowledge, the use of multiple compatibilizers, including maleated polyolefins/anhydride polyolefins, and functionalized polyoefm copolymer/terpolymer for polyamide and PBT or PET has not been reported previously. 4.3 Materials

4.3.1 Polymers

Nylon / Polyamide

Any commercially available polyamides (PA) resin may be used in the biocomposites fabrication of the present invention, including neat PA6, and PA6,6. Nylon used in this invention may also included commercially available Nylon 6 resin, from BASF Ultramid® B27E, Dupont Zytel® 7301 and Nylon 6,6 resin from BASF Ultramid® A3KUNQ601, Dupont Zytel® 101L.

Recycled nylon / recycled polyamide

Recycled nylon / recycled PA6 is referring to the post-consumer use of nylon, such as from carpet industry. Recycled nylon contains minor amounts of polypropylene (4-20 wt. %) and additives. As the recycled nylon is not consistent in polymeric ratio and has unknown additives, recycled nylon is not well suited as a standalone plastic substitute to virgin or neat PA. The recycled carpet used in the examples was supplied by Competitive Green Technologies, Leamington, Canada.

Polybutylene terephthalate

Polybutylene terephthalate (PBT) is an engineering thermoplastic polyester which may be blended with a polyamide in the present invention. The PBT may be any commercially available resin made from terephthalic acid and l,4-butanediol through a condensation reaction. PBT used in this invention is from Celanex grade 2000-3. Polyethylene terephthalate

Polyethylene terephthalate) (PET) may be any commercially available PET. The intrinsic viscosity of the PET may be 0.7-0.9 deciliters per gram (dL/g), with a crystallinity > 35%, and a melting point of approximately 220-250 °C. The PET used in this invention is from DAK Americas, grade Laser+ B90A, Pennsylvania, USA

Recycled Polyethylene terephthalate

Recycled polyethylene terephthalate) (rPET) may be any commercially available recycled PET flakes/pellets or obtained from regrind PET. rPET has lower molecular weight and inferior properties compared to neat PET, making rPET unsuitable in high-end applications. The rPET is food grade (food & drug administration approved for conditions of use E-G or better), and a melting point of approximately 225-250°C. The rPET used in this invention is from Phoenix Technologies food grade LNO™, Ohio, UTS A.

Poly (lactic acid)

Poly (lactic acid) (PLA) was used in this biocomposites formulation as a flow enhancer. The PLA used may be commercially available or synthesized resin made from lactic acid. The number average molecular weight of poly (lactic acid) may be in the range of 50000 - 450000 while polydispersity index may be in the range of 1 -3. The poly (lactic acid) having the molecular weight in the range of 100000 - 250000 is preferred from melt viscosity considerations. The PLA used in this invention is from the injection grade PLA available from Natureworks LLC as Ingeo biopolymer 3251D. PLA in the blends and composites may constitute from about 0 to about 3% by weight. Preferably, the PLA used is injection molding grade with high melt flow index to improve the processability of the composite.

4.3.2 Additives - Compatibilizers

Additives may be used in this invention to improve the miscibility of polyamide with PBT, rPET and rPA6 as well as to improve the notched impact strength of the composites.

Maleated polyolefins / Anhydride polyolefins

Fusabond® P353 (maleic anhydride modified polypropylene) and Fusabond® N493 (anhydride modified ethylene copolymer) from DuPont were used as commercially available impact modifiers and compatibilizers. Compatibilizing additives may also be other commercial maleated co- polymer such as maleated polyolefins (MAPP and MAPE), or multi-phase compatibilizers containing both polyamide and polyolefin.

Styrene Maleic Anhydride Copolymer

Styrene Maleic Anhydride Copolymer (SMA)®l7352 is a partial mono ester of SMA and a mixture of two alcohols. SMA 17352 is available in flake or powder form. SMA 17352 can be utilized to improve filler and matrix compatibility, dispersion in thermoplastic materials. The SMA used in this invention range from 1% to 5% by weight. SMA is used together with recycled carpet / recycled PET to enhanced the compatibility with nylon.

Functionalized Polyolefin Copolymer/Terpolymer

The functionalized polyolefin copolymer/terpolymer may be used as one of the glycidyl methacrylate (GMA) functionalized polyolefin copolymer and may include any of the following functional groups in various weight ratios regarding to composition: ethylene/n-butyl acrylate/glycidyl methacrylate, ethylene/methyl acrylate/glycidyil methacrylate, ethylene/glycidyl acrylate, glycidyl methacrylate-poly(ethylene octane). Any other commercially available impact modifier consists of acrylate ethylene terpolymer (EBA-GMA) can be used for the composites fabrication. An ethylene/n-butyl acrylate/glycidyl methacrylate available under trade name Elvaloy PTW manufactured by DuPont is preferred as the most efficient. The EBA-GMA content used in this invention range from 3-9% by weight.

Heat Stabilizer

Copper based heat stabilizer (antioxidants) for polyamides was used to prepare the biocomposites. The commercial heat stabilizer used in this invention is from Brugolen®H series, grade H321. The amount used may be from 1-2 phr. Further commercial additives based on copper salts may be added as heat stabilizers for the biocomposites.

4.3.3 Additives - Reinforcing materials

Biosourced carbon

The biocarbon used in this invention may be produced through the pyrolysis of biomass from one or more sources, such as plant fiber or agricultural residues that contain plant fiber. The pyrolysis is completed in an oxygen-limited environment at temperatures between 350 and 900 °C. The different pyrolyzed biocarbon may be further modified by grinding, milling and separation to control its particle size and aspect ratio. The biocarbon used in the invention is produced from BDDC laboratories or provided by Competitive Green Technology, Leamington, Canada. Nanoclay

The nanoclay used in this invention may be an organomodified montmorillonite clay, modified with octadecylamine for compatibility with the polyamide matrix.

Recycled carbon fiber

Recycled carbon fiber may be any commercially available chopped carbon fiber obtained from post-industrial waste streams (Minifibers Inc, USA). The carbon fibers may be between 3, 6, 12 and 24 mm in length.

Long carbon fiber

The long carbon fiber/nylon 6 master batch process through pultrusion technique or extrusion may be used in this invention during injection moulding. The long carbon fiber/PA6 maybe in the ratios of 20/80, 30/70 and 40/60. The long carbon fiber/nylon master batch used in this invention is from PlastiComp grade Complet LCF60-PA6 1005 NAT Composite Pellets.

The blends and composites performance after incorporation of wastes and recycled resins usually results in inferior performance. This invention utilizes and convert various waste stream materials into value-added high-performance engineering plastic-based biocomposites with high recycled content. These include blends of PA6/PBT, PA6/PET, PA6/rPA6 and PA6/rPET and various combination thereof. The developed novel nylon-based biocomposite is lighter (-20%) than conventional nylon-based composite with glass fiber and talc, has high stiffness (modulus >9GPa), has higher sustainable content (-60%) through addition of recycled engineering plastics and recycled fiber addition and is cost competitive compared to the aforementioned nylon composites. As there is normally a tradeoff in the performance with the inclusion of fillers, they are most commonly used in virgin plastics. Likewise, the addition of recycled plastic into virgin plastic tends to reduce the mechanical performance as well making it difficult to include additional fillers as further mechanical loss occurs. In this invention, the utilization of both a biofiller and recycled plastic content together is able to maintain a high-performance in properties while increasing the sustainable content above that of using only one of the constituents alone. This is attained through the mutli-functional compatibilizers which enhance the interfacial adhesion between the polyamide and recycled plastic in the matrix and in presence of the filler. This invention help maintains a cleaner environment by proper use of waste materials instead of incineration or landfilling by following a circular economy approach, with a portion of recycled content being incorporated that do not have the same degree of performance as the virgin counterparts.

4.4 Processing

Polyamide (PA6, PA6,6), recycled polyamide (rPA6), poly (lactic acid), polyester (PET), recycled polyester (rPET) and long carbon fiber master batch were dried at 80 °C for at least 12 hours prior to processing in order to remove moisture content which is undesirable for processing while biocarbon was dried at 105 °C until constant weight.

The formulations of the mentioned biocomposites and nanocomposites may be prepared via melt blending in a twin-screw extruder. This may include a semi-pilot scale continuous twin-screw extruder (DSM Xplore Micro 15 cc twin screw extruder with DSM Micro 12 cc injection molding unit), as well as a lab-scale semi-batch twin screw extruder (Leistritz co-rotating twin-screw extruder with Arburg Injection Molder), at temperatures between 240-280 °C. The samples to be tested may be produced via injection moulding with melt temperatures between 250-280 °C with mould temperatures range from 30-60 °C. Fiber reinforcements (rCF and LCF) were added in a late feeding zone in the extruder or in the hopper in Arburg to reduce residence time, which reduces the shearing and breakdown of the individual fibers. Maintaining the integrity of the fibers increases their reinforcing effect on the biocomposite.

4.5. Testing and Characterization:

The mechanical tests i.e. tensile, flexural, Charpy impact, notched impact tests were performed according to ASTM D638 (Type IV), D790, D4812 and D256, respectively. The tensile and flexural tests were performed using an Instron model 3382 Universal Testing Machine. The tensile test was performed with a crosshead speed of 50 mm/min for neat polymers and 5 mm/min for composite samples and the flexural test were carried out at crosshead speed of 14 mm/min on 52 mm span length setup with flexural strain of 5% extension, unless early failure occurs. Notched Izod impact and Charpy impact test were carried out using a TMI 43-02 Monitor Impact Tester using 5 ft-lb Izod impact pendulum (Testing Machines Inc., New Castle, DE, USA). The samples were notched in a notch cutter according to ASTM D256 dimensions before the impact test. All the mechanical data reported were obtained from a total of 5 specimens for each sample and the mean and standard deviation were calculated.

The heat deflection temperature (HDT) measurement was carried out using dynamic mechanical analysis (DMA) Q800 from TA-Instruments, USA. The sample dimension with 50 mm x 12 mm x 3 mm (length x width x thickness) was setup in a 3 -point bending clamp in DMA controlled force mode with an applied stress of 0.455 MPa according to ASTM D648 standard. The temperature ramp rate was 2 °C/min and HDT was determined as a temperature at which the deflection changes of samples more than 250 pm.

Melt flow index (MFI) was determined using a Qualitest 2000A melt flow indexer at 250 °C. with 2.16 kg of weight, according to ASTM D1238. MFI samples were dried at 80 °C for at least 6 hours prior to MFI testing.

Density was measured using an Alfa Mirage MD-300S densimeter.

5. Example of the formulations

Examples 1 - Heat aging performance of different polyamides and engineering polyesters Table 1: Heat aged PA6, PA66, PET and PBT conditions.

Table 2: Mechanical properties of conditioned PA6, PA 6,6, PET and PBT.

Conditioned PA6, PA6,6, PET and PBT are given in Table 1 and Table 2. After thermal aging at elevated temperature for 1000 hours following ASTM D3045, the change in mechanical properties is evident for PA6, PA66, PET and PBT. It is clear that engineering polyesters PET and PBT are far superior in maintaining its tensile and flexural strength after thermal aging (Table 2) as compared to polyamide. Where most of the mechanical properties of PA6 and PA6,6 were reduced, these properties are in fact enhanced in PET and PBT. On this basis, PET and or PBT was selected as a blending component to improve the overall durability and retention of the mechanical properties in PA6 during thermal aging.

Examples 2 - Mechanical properties and toughness improvement for PA6/PBT blends with different compatibilizers

Table 3: Polymer blends with multi-phase compatibilizers.

*ID 9-12 were processed with DSM twin screw extruder micro-compounder.

*ID 13-16 are carried out in Leistritz twin screw extrusion followed by injection moulding. Table 4: Mechanical properties of polymer blends with multi-phase compatibilizers.

As showed in Table 4, the binary and ternary blends of the present invention, PA6, PBT and recycled nylon, have been effectively compatibilized to produce high toughness blends that exceeds the theoretical properties expected by the rule of mixture.

Examples 3 - Mechanical properties enhancement with biosourced carbon pyrolyzed from different biomasses

Table 5: Effect of different types of biocarbon-reinforced PA6 (30/70).

In the example given in Table 5, the effect of biocarbon surface chemistry, source of biocarbon and pyrolysis temperature on the properties of PA 6-biocarbon biocomposites were investigated. These biocarbons are incorporated into the PA6 matrix at 30 wt. % loading to fabricate biocomposites. It was observed that the modulus was higher for biocarbon pyrolyzed at a higher temperature, while functional groups were absent in this biocarbon. The composite containing biocarbon pyrolyzed at a lower temperature revealed a higher strength and a greater affinity with the PA6.

Examples 4 - Mechanical performance of PA6 and PA66 reinforced biocarbon and long fibers

Table 6: Composition of biocarbon/P A6 biocomposites and biocarbon/P A6, 6 biocomposites with LCFMB and LGFMB.

*The above compounding formulation are carried out in Leistritz twin screw extmsion followed by injection moulding.

*LGFMB - Long glass fiber/P A6 master batch

*LCFMB - Long carbon fiber/P A6 master batch

*Both Miscanthus and wood biocarbon used in the biocomposites formulations are produce with batch pyrolysis process at 650 °C and 4 hours ball-milling.

*The long carbon fibers or long glass fiber master batch were introduce during injection moulding only.

$The long carbon fibers or long glass fiber master batch were introduce during Leistritz twin screw extmsion.

Table 7: Effect of MAPP compatibilizer on the mechanical properties of biocarbon/P A6 biocomposites with LCFMB and LGFMB.

*The long carbon fibers master batch were introduce during injection moulding only.

Table 8: Effect of different processing techniques on the mechanical performance of biocarbon/PA6 biocomposites with LCFMB and LGFMB.

*The long carbon fibers or long glass fiber master batch were introduce during injection moulding only.

The long carbon fibers or long glass fiber master batch were introduce during Leistritz extrusion.

The incorporation of long fiber master batch during injection moulding is more advantages

(advantageous?) than addition of all the material in twin screw extruder. Moreover, long carbon fiber master batch composites showed higher mechanical properties compared to long glass fiber master batch composites as well as the hybrid of both fibers. Table 9: Mechanical properties of hybrid of PA6, 6/biocarbon biocomposites with LCFMB and LGFMB.

*The long carbon fibers master batch were introducing during injection moulding only.

Table 10: Mechanical properties of PA6/recycled PA6/biocarbon-based biocomposites with LCFMB and LGFMB.

*The long carbon fibers master batch were introduce during injection moulding only.

Examples 5 - Dimensional stability enhancement of PA6/PA66/PBT/PET/rPET blends hybrid biocomposites by addition of small amount of nanoclay

Table 11: Formulations for nano-enhanced biocomposites.

Table 12: Mechanical performance and coefficient of linear thermal expansion (CLTE) of nano- enhanced biocomposite formulations.

Table 12 shows the mechanical properties and coefficient of linear thermal expansion (CLTE) of the nanocomposites in this invention. Blend ID 52 shows the mechanical and thermal properties of neat PA6. In Blend 53, the addition of 30 wt.% biocarbon enhances the tensile/flexural strength and modulus, HDT, and CLTE compared to neat nylon. The hybridization of biocarbon (28.5 wt.%) and nanoclay (1.5 wt.%) in Blend 54 yields superior mechanical properties compared to Blend 53. The stiffness and flexural strength are both significantly enhanced by addition of only 1.5 wt% of nanoclay. The HDT is further improved from 175.4 to 190.3 °C, and the CLTE is reduced significantly.

The key finding is that through hybridization of biocarbon and nanoclay, polyamide composites can be produced with high bio-based content (~30 wt.%), using only a very small amount of nanoclay, which possess excellent thermomechanical properties. The necessity of only a small amount of nanoclay due to hybridization with biocarbon contributes to the cost-performance efficiency of the biocomposites. A small amount of nanoclay creates nanocomposites with improved properties, while remaining cost-effective. The combination of nanoclay with biocarbon provides superior CLTE than composites with nanoclay alone.

Table 13: Mechanical performance of nano-enhanced polyamide blend biocomposite formulations with more than 30% sustainable and recycled content.

Polyamide blending with PBT is employed to preserve tensile properties during thermal aging. A maleated polypropylene (MAPP) compatibilizer in combination with EBA-GMA is used to promote miscibility as well as enhance toughness in this polymer blend. Around 3% of MAPP is used, and between 5-7% of EBA-GMA. Blend 55 demonstrates a PA6/PBT blend in which biocarbon is hybridized with recycled carbon fiber to create a biocomposite with high bio-based content (19%) and recycled content (13%). Due to the unique compatibilization with MAPP and modification with EBA-GMA, this blend maintains an impact strength of 73.6 J/m, superior to neat PA6, while also possessing very high tensile/flexural strength and modulus with a relatively low density of 1.237 g/cm ³ .

Blends 56-60 demonstrate that by incorporating nanoclay as a hybrid reinforcement, a lower amount of recycled carbon fiber can be used while maintaining high mechanical properties. A tensile modulus greater than 8 GPa can be maintained while reducing the carbon fiber content to 7%. Further, 1.0 phr of a copper salt-based heat stabilizer is added to improve the thermal durability to counter the environmental aging.

Blend 61 demonstrates that by replacing 20% of the PA6 content with PA6,6, the tensile strength is increased by 7 MPa, the tensile modulus by 800 MPa, the flexural strength by 17 MPa, and the flexural modulus by 1100 MPa compared to Blend 13, while maintaining the same amount of reinforcement as used in Blend 60.

Blends 62 and 63 demonstrate a material in which the amount of recycled carbon fiber is reduced and replaced proportionally with biocarbon. This yields a material which can demonstrate tensile modulus greater than 7 GPa and flexural modulus greater than 6 GPa, while using only 5% recycled carbon fiber by weight, and containing 27% bio-based content.

Blends 65 and 66 demonstrate that the same system can be produced in which the PBT phase is replaced by PET and recycled PET, while maintaining excellent tensile and flexural strength and modulus. Example 6 - Significant reduction in weight/density of the invented nylon-based biocomposites in comparison to conventional nylon composites formulations

Table 14: Density comparison of Nylon 6-based biocomposite vs. conventional 40/60 glass and talc filled nylon composites.

Our developed PA6/rPA6-based biocomposites showed relatively low densities (-20% reduction) as compared to the popular conventional PA6/talc/glass fiber composites. A blend of nylon/rPA6/rPET was designed with improved mechanical performance (>100 MPa tensile strength and > 9000 MPa of tensile modulus, reduced density as compared to conventional 40/60 nylon composites with 15 wt.% glass fiber and 25 wt.% talc.

Example 7 - Performance of high sustainable and recycled plastic content in PA6-based biocomposites

Table 15: High sustainable and recycled plastic content in PA 6-based biocomposites with hybrid fillers formulations.

*The above compounding formulation are carried out in Leistritz twin screw extrusion followed by injection moulding except samples no. 73, 74, 75, 76 are carried out in DSM.

*The biocarbon used are pyroloyzed from miscanthus or wood chips in the ranged from 350 °C to 900 °C with different milling time and particles size.

*Hybrid: Two different biocarbon from low and high pyrolyzed temperature.

*HS: heat stabilizers

*Recycled carbon fibers was added in the side feeder of the twin screw extruder.

*The long carbon fibers master batch were introduce during injection moulding only.

Examples 8 - Effect of long fiber master batch in the PA6-based biocomposites

Table 16: Addition of long carbon fiber/P A6 (40/60) master batch during injection moulding.

* The biocarbon used in the biocomposites contain 26 wt% of wood biocarbon pyrolyzed at 650 °C.

* rCF - Recycled carbon fiber, LCFMB - Long carbon fiber master batch

We incorporate long carbon fiber master batch into the different compatibilized nylon-based biocomposites to further enhance the mechanical strength of the developed biocomposites. The tensile and flexural strength increased approximately -30%; tensile modulus and flexural modulus increased approximately -20% with only 3% addition of long carbon fiber.

Examples 9 - Effect of hybridized biosourced carbon in the PA6/rPA6-based biocomposites formulations

Table 17: Effect of hybridized biosourced carbon in the PA6/rPA6-based biocomposites formulations.

* The biocarbon used in the biocomposites formulations are produce with batch pyrolysis process of wood biomass at different temperature. The PA6/rPA6-based biocomposites reinforced with hybridized biocarbon exhibited higher tensile modulus and flexural modulus as compared to single type biocarbon reinforcement.

Example 10 - Mechanical performance of high sustainable and renewable content for PA6/rPA6-based hybrid biocomposites.

Table 18: Mechanical properties of high sustainable and renewable content for PA6/rPA6-based hybrid biocomposites.

* The biocarbon used in ID 73, 74, 77, 78 is hybridization of batch pyrolyzed wood biomass at 350 °C and continuous pyrolyzed wood biomass at 650 °C respectively.

* The biocarbon used in ID 72 is hybridization of batch pyrolyzed wood biomass at 900 °C and continuous pyrolyzed wood biomass at 650 °C respectively.

*The biocarbon used in ID 76 is from continuous pyrolysis of Miscanthus biomass at 650 °C.

*The biocarbon used in ID 71 is from batch pyrolysis of wood biomass at 900 °C. As shown in Table 18, the incorporation of high sustainable/recycled content (>50 wt.%) in the hybrid biocomposites formulation with the presence of the compatibilizers exhibited exceptional mechanical properties (tensile strength > 100 MPa, tensile modulus -9000 MPa, flexural modulus > 7000 MPa, notched impact strength -35-60 J/m. In particular, for ID: 75, tensile strength showed >130 MPa, tensile modulus >10 GPa, flexural modulus -7.0 GPa and notched impact strength -45 J/m.

Examples 11 - Melt flow enhancement of PA6/rPA6/rPET hybrid biocomposites by addition of PLA

Table 19: Improving the melt flow index of PA6/rPA6/rPET -based biocomposites by addition of PLA.

* The biocarbon used in the biocomposites formulations are produce with batch pyrolysis process of wood biomass at 900 °C temperature.

*The biocomposites samples from ID79-ID80 were developed in the DSM twin screw mini compounder followed by injection moulding.

The high loading of fillers in a composites could result in poor flowability of the matrix which is undesirable for injection moulding parts. Flow enhancer usually applied for high filler loading of injection moulding parts. We found that the incorporation of PLA in the formulation aid in the flowability of the composites. The melt flow index (MFI) value of the biocomposites increase almost 2X after incorporation of low amount of PLA in the formulation. Examples 12 - Comparison of different biocarbon reinforcement in PA6/rPA6/rPET biocomposites

Table 20: Comparison of different biocarbon reinforcement in PA6/rPA6/rPET biocomposites.

As presented in Table 20, the biosourced carbon derived from wood biomass showed higher mechanical properties as compared to the biosourced carbon derived from Miscanthus biomass.

Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification, improvement and variation of the inventions embodied therein herein disclosed may be resorted to by those skilled in the art, and that such modifications, improvements and variations are considered to be within the scope of this invention.

In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group.

All publications, patent applications, patents, and other references mentioned herein are expressly incorporated by reference in their entirety, to the same extent as if each were incorporated by reference individually. In case of conflict, the present specification, including definitions, will control.

It is to be understood that while the invention has been described in conjunction with the above embodiments, that the foregoing description and examples are intended to illustrate and not limit the scope of the invention. Other aspects, advantages and modifications within the scope of the invention will be apparent to those skilled in the art to which the invention pertains.

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